Search Publications
Possible detection of two giant extrasolar planets orbiting the eclipsing polar UZ Fornacis
O'Donoghue, Darragh; Ramsay, Gavin; Buckley, David A. H. +11 more
We present new high-speed, multi-observatory, multi-instrument photometry of the eclipsing polar UZ For in order to measure precise mid-eclipse times with the aim of detecting any orbital period variations. When combined with published eclipse times and archival data spanning ∼27 years, we detect departures from a linear and quadratic trend of ∼60…
Observational Constraints on Submillimeter Dust Opacity
Bieging, John H.; Wilner, David J.; Shirley, Yancy L. +4 more
Infrared extinction maps and submillimeter dust continuum maps are powerful probes of the density structure in the envelope of star-forming cores. We make a direct comparison between infrared and submillimeter dust continuum observations of the low-mass Class 0 core, B335, to constrain the ratio of submillimeter to infrared opacity (κsmm
The Herschel Virgo Cluster Survey. IX. Dust-to-gas mass ratio and metallicity gradients in four Virgo spiral galaxies
Bianchi, S.; Smith, M.; Fritz, J. +20 more
Context. Using Herschel data from the open time key project the Herschel Virgo Cluster Survey (HeViCS), we investigated the relationship between the metallicity gradients expressed by metal abundances in the gas phase as traced by the chemical composition of HII regions, and in the solid phase, as traced by the dust-to-gas mass ratio.
Aims: W…
Inferring the magnetic field vector in the quiet Sun. I. Photon noise and selection criteria
Borrero, J. M.; Kobel, P.
In the past, spectropolarimetric data from Hinode/SP were employed to infer the distribution of the magnetic field vector in the quiet Sun. While some authors found predominantly horizontal magnetic fields, others favor an isotropic distribution. We investigate whether it is actually possible to accurately retrieve the magnetic field vector in reg…
Solar magnetic feature detection and tracking for space weather monitoring
Bloomfield, D. S.; Gallagher, P. T.; McAteer, R. T. J. +1 more
We present an automated system for detecting, tracking, and cataloging emerging active regions throughout their evolution and decay using SOHO Michelson Doppler Interferometer (MDI) magnetograms. The SolarMonitor Active Region Tracking (SMART) algorithm relies on consecutive image differencing to remove both quiet-Sun and transient magnetic featur…
Cluster statistics of thin current sheets in the Earth magnetotail: Specifics of the dawn flank, proton temperature profiles and electrostatic effects
Petrukovich, A. A.; Zelenyi, L. M.; Nakamura, R. +1 more
In this paper we use the statistics of 70 crossings by the Cluster mission to study and compare properties of thin current sheets observed at the dawn and dusk flanks of the Earth magnetotail. Special attention is devoted to the current sheet embedding: we define the degree of the current sheet embedding as be = Bext/B0<…
A Submillimeter Mapping Survey of Herbig AeBe Stars
Sandell, Göran; Weintraub, David A.; Hamidouche, Murad
We have acquired submillimeter observations of 33 fields containing 37 Herbig Ae/Be (HAEBE) stars or potential HAEBE stars, including SCUBA maps of all but two of these stars. Nine target stars show extended dust emission. The other 18 are unresolved, suggesting that the dust envelopes or disks around these stars are less than a few arcseconds in …
The Edge of the Milky Way Stellar Disk Revealed Using Clump Giant Stars as Distance Indicators
Minniti, D.; Saito, R. K.; Alonso-García, J. +2 more
We use the clump giants of the disk as standard candles calibrated from Hipparcos parallaxes in order to map their distribution with two new near-infrared surveys of the Galactic plane: UKIDSS-GPS and VISTA Variables in the Vía Láctea (VVV). We explore different selection cuts of clump giants. We conclude that there is an edge of the stellar disk …
The mineralogy of late stage lunar volcanism as observed by the Moon Mineralogy Mapper on Chandrayaan-1
Head, J. W.; Besse, S.; Boardman, J. +11 more
The last major phases of lunar volcanism produced spectrally unique high-titanium basalts on the western nearside of the Moon. The Moon Mineralogy Mapper (M3) on Chandrayaan-1 has provided detailed measurements of these basalts at spatial and spectral resolutions necessary for mineralogical interpretation and mapping of distinct composi…
Further X-ray observations of EXO 0748-676 in quiescence: evidence for a cooling neutron star crust
Degenaar, N.; Wijnands, R.; Ray, P. S. +8 more
In late 2008, the quasi-persistent neutron star X-ray transient and eclipsing binary EXO 0748-676 started a transition from outburst to quiescence, after it actively accreted for more than 24 yr. In a previous work, we discussed Chandra and Swift observations obtained during the first 5 months of this transition. Here, we report on further X-ray o…